The present invention relates to a warning ashtray for smokers, more particularly, to a completely automatic warning ashtray which indicates to the user when it is time to dispose of accumulated ash on a lit cigarette. Because operation of the ashtray is keyed to the natural actions of the smoker, no controls need to be remembered nor extra motions be made in order to accrue the advantages derived from the invention's use. An ashtray of this nature is desirable because of its potential to prevent the occurrence of burns to furniture, desks, etc., resulting from temporarily forgotten or unattended cigarettes, and also from persons who may have fallen asleep with a lit cigarette. Use of the ashtray of the present invention may prevent a major fire from occurring.
A variety of warning systems associated with ashtrays are known. The prior art ashtrays generally have the disadvantage, however, that the user must remember to perform one or more steps in order to activate the alarm system. The inevitable result is non-use of the alarm system, thereby depriving the smoker of the ashtray's purported warning function. Moreover, the prior art safety ashtrays are generally directed to indicating a total burn time, disregarding the lesser interval at which ashes must be discarded, which can again result in the prior art device's failure to achieve its safety objective.
For example, U.S. Pat. No. 4,520,345 to Smit discloses an ashtray in which the manual opening of a normally closed lid activates an electronic timer which, at the end of a predetermined timing cycle, will trigger an alarm. If the lid is closed prior to the end of the cycle, the timer is deactivated. One of the problems with that ashtray, however, is that the user is required to work a manual control to open and close the lid for each cigarette. In addition, the timer system is designed to indicate total burn time, a period which can be undesirably long for a warning ashtray.
U.S. Pat. No. 4,428,386 to Alloway discloses what is called a safety ashtray in which the user must manually lift the entire ashtray, disposed on a vertically reciprocating push/pull switch, to close a circuit. In addition, the user must rotate a timer dial to a desired time interval. At the end of a time interval an alarm will sound unless the switch has been first opened by depressing the ashtray. This ashtray suffers from the same disadvantages of the prior art generally, in that the user must both remember and desire to work manual controls in order for the device to performs its intended function.